Sheet registration and feeding

ABSTRACT

A set of sheets in registered in a stack on a pin means and adjacent guide means. The sheets are fed seriatim from the stack by feed means operating with a predetermined force. The pin means have a semicircular cross-sectional configuration. Each sheet in the set contains a registration edge for registering each sheet with the guide means and an aperture for registering each sheet with the pin means. The aperture is positioned in a prescribed relationship to and closely adjacent the registration edge. The aperture edge and the registration edge define a holding strip of varying width. The narrowest portion of the holding strip defines a separation region of a predetermined width between the aperture and the registration edge. Portions of the aperture edge are shaped for registering each sheet with a pin means adjacent the separation region. Portions of the aperture edge in common with the holding strip and adjacent the registering portions of the aperture edge on opposite sides of the registering portions from the separation region define two clearance edges. The two clearance edges converge toward each other in a direction toward the registration edge and thereby enable the holding strip to deflect to concentrate tension in the separation region when the holding strip of a registered sheet is forced against the pin means. The two clearance edges are preferably straight edges. The feed means include feed legs which are positioned on each side of the pin means for engaging the outside registered sheet at positions adjacent the registration edge beyond each side of the aperture; and the feed legs are spaced apart by a predetermined distance for causing deflection of the holding strip for concentrating tension in the separation region when the holding strip is forced against the pin means by the feed legs feeding the registered and engaged sheet from the stack. The feed legs are also spaced apart by a predetermined distance for enabling the feeding of the engaged sheet from the stack; that is, the feed legs must be placed close enough together to cause sufficient force to be applied between the holding strip and the pin means to enable the separation of the holding strip upon the operation of the feed means. The feed means include means for engaging the feed legs with the registration edge of an outside registered sheet for enabling the feed legs to push against the engaged registration edge to feed the engaged sheet from a registered stack. The feed means also include means for applying a force to compress the stack for aligning the registration edge of the outside registered sheet with the feed legs to enable the engagement of the feed legs with the registration edge. The feed legs are variably disposed to the holding means in response to variations in the size of a stack; and the feed means include spring means for providing the force which is applied for compressing the stack of sheets. These spring means are operatively responsive to a variation in the disposition of the feed means in response to a reduction in the size of the stack for decreasing the provided applied compressive force as the size of the stack is reduced.

United States Patent Primary Examiner-Joseph Wegbreit Attorney-Kinney,Alexander, Sell, Steldt & Delahunt ABSTRACT: A set of.sheets inregistered in a stack on a pin means and adjacent guide means. Thesheets. are fed seriatim from the stack by feed means operating with apredetermined force. The pin means have a semicircular cross-sectionalconfiguration. Each sheet in the set contains a registration edge forregistering each sheet with the guide means and an aperture forregistering each sheet with the pin means. The aperture is positioned ina prescribed relationship to and closely adjacent the registration edge.The aperture edge and the registration edge define a holding strip ofvarying width. The narrowest portion of the holding strip defines aseparation region of a predetermined width between the aperture and theregistration edge Portions of the aperture edge are shaped forregistering each sheet with a pin means adjacent the separation region.Portions otthe aperture edge in common with the holding strip andadjacent the registering portions of the aperture edge on opposite sidesofthe registering portions from the separation region define twoclearance edgesv The two clearance edges converge toward each other in adirection toward the registration edge and thereby enable the holdingstrip to deflect to concentrate tension in the separation region whenthe holding strip of a registered sheet is forced against the pin means.The two clearance edges are preferably straight edges. The feed meansinclude feed legs which are positioned on each side of the pin means forengaging the outside registered sheet at positions adjacent theregistration edge beyond each side of the aperture; and the feed legsare spaced apart by a predetermined distance for causing deflection ofthe holding strip for concentrating tension in the separation regionwhen the holding strip is forced against the pin means by the feed legsfeeding the registered and engaged sheet from the stack. The feed legsare also spaced apart by a predetermined distance for enabling thefeeding of the engaged sheet from the stack; that is, the feed legs mustbe placed close enough together to cause sufficient force to be appliedbetween the holding strip and the pin means to enable the separation ofthe holding strip upon the operation of the feed means. The feed meansinclude means for engaging the feed legs with the registration edge ofan outside registered sheet for enabling the feed legs to push againstthe engaged registration edge to feed the engaged sheet from aregistered stack. The feed means also include means for applying a forceto compress the stack for aligning the registration edge of the outsideregistered sheet with the feed legs to enable the engagement of the feedlegs with the registration edge. The feed legs are variably disposed tothe holding means in response to variations in the size of a stack; andthe feed means include spring means for providing the force which isapplied for compressing the stack of sheets. These spring means areoperatively responsive to a variation in the disposition of the feedmeans in response to a reduction in the size of the stack for decreasingthe provided applied compressive force as the size of the stack isreduced.

SHEET REGISTRATION AND FEEDING CROSS-REFERENCE TO RELATED APPLICATIONThis application is related to the copending application filed by JohnL. Roche on Feb. 10, 1969, Ser. No. 798,016, and to the copendingapplication filed by one of the present inventors, Segwald J. Reckdahl,on Oct. 24, i969, Ser. No. 869,002.

BACKGROUND OF THE INVENTION The present invention relates to sheetfeeding and registration and is particularly directed to a combinationwherein a stacked set of sheets is registered on a pin means in a givenposition, in which given position registration of each remaining sheetin the stack is maintained as sheets are fed seriatim from the stack.

A specific application of the present invention is with a test gradingdevice, such as is described in U.S. Pat. application Ser. No. 798,016by Roche, filed on Feb. 10, 1969, wherein a set of stacked answer sheetsare held by pin means in a position for scanning of answer indicationareas placed on each answer sheet, and wherein each scanned answer sheetis individually torn from said pin means for removal from the scanningposition.

In accordance with the description of the test grading device set forthin the Roche application, a stack of answer sheets, each having apredetermined configuration of answer indication areas placed thereon ina predetermined relationship to a registration edge of the sheet, isplaced on supporting means in a given position for the scanning of theanswer indication areas of each sheet. This given position is defined byguide means such as bars which are disposed adjacent the supportingmeans. Once the stack of sheets is in the given position, a pin meanssuch as a sharpened needlelike pin is driven through the stack in orderto hold the sheets in the given position. The answer indication areas ofthe outside sheet in the stack are scanned and the answer indicationswhich are sensed in the scanned answer indication areas are comparedwith answer indications sensed from corresponding answer indicationareas of an answer key. From such comparisons, each answer sheet isscored. Following the scanning of each sheet,

the scanned sheet is engaged by removal means, such as feed means, whichfeed the scanned sheet from the pin, thereby removing the scanned sheetfrom the scanning position.

The predetermined configuration of answer indication areas is placedupon the answer sheet in a prescribed relationship to the registrationedge of the sheet so that the scanning of the answer indication areas ofthe answer sheet is synchronized with the scanning of the correspondinganswer indication areas of the answer key. The answer key has a fixedposition in relation to the guide means and in relation to the stackholding position of the pin means. The degree to which each answer sheetofa stack can be placed in a position corresponding with the position ofthe other sheets in the stack, or can be positioned for insuring thatthe scanning of the answer indication areas of each answer sheet issynchronized with the scanning of the corresponding answer indicationareas of an answer key, is limited by human ability and diligence inuniformly stacking the sheets when placing them against the guide meansand by the holding capability of the pin means.

Certain difficulties have arisen in feeding of the above describedanswer sheet ofthe prior art. For example, when the sheets are separatedfrom the needlelike pin means, the tearing is ragged and there is anappreciable residue of debris resulting from the tearing. When largerpin means are used, multiple tearing of the sheets also results. Also,there is a tendency of the prior art answer sheets to either bedouble-fed or misfed from the given position upon operation of thefeeding means.

in order to provide an answer sheet which can be registered forsynchronized scanning in a test grading device and also be reliably fedfrom the holding means of the test grading device,

a novel set of answer sheets was-invented. This novel set of answersheets is described in the copending U.S. Pat. application by one of thepresent inventors, Segwald J, Reckdahl, filed on even date herewith.

The feed means described in the aforementioned Roche application includetwo feed legs which are disposed for engaging the exposed surface of theoutside sheet of a stack of registered sheets. The feed legs exert adownward pressure on the stack of registered sheets. The feed legs alsoinclude gripping pads for engaging the outside registered sheet. Thefeed legs are pivotally mounted to an axis which is above and to therear of the stack of registered sheets in relation to the direction oftravel of the feed legs. Therefore, when the feed means operate, thefeed legs exert sufficient downward and forward pressure on the engagedoutside registered sheet of the stack to tear it from the pin means.Upon the engaged sheet tearing from the pin means, the pivotally mountedfeed legs pivot off the stack of answer sheets and the downward force isnot transmitted to the remaining sheets in the stack. With this feedingdevice, however, there are limitations in the size of the paper stacksince the downward force applied to the stack appreciably increases asthe size of the stack is reduced. When using this feed means with alarge stack of registered sheets, there may be either misfeeding at thetop of the stack or double-feeding-at the bottom of the stack, or both.

Another problem is the accumulation of paper dust on the gripping padsafter a certain number of sheets have been fed, thereby reducing thecoefficient of friction between the gripping pads and the outsideengaged registered sheet. As a result, misfeeding increases as thiscoefficient of friction is reduced, unless the gripping pads areperiodically cleaned.

It is an object of the present invention to provide a sheet registrationand feeding mechanism which, when combined with a set of sheets, such asa novel set of answer sheets described in the aforementioned copendingapplication, provides registration of the sheets and reliable seriatimfeeding of the sheets from a registered position.

It is desirable that the probability of double-feeding or misfeeding ofthe sheets be reduced.

it is also desirable that each sheet consistently tear in a definedseparation region having a predetermined width, thereby minimizing therange of the predetermined feeding force. I

It is additionally desirable that the tearing of each sheet not beragged since ragged tearing inhibits uniform stacking of fed sheets forscanning of the opposite surface thereof with a second registration edgepositioned against the guide means.

It is further desirable that the residue of debris resulting from thetearing be appreciably minimized since the debris tends to inhibitconsistent feeding of the remaining sheets.

SUMMARY OF THE INVENTION The present invention provides a sheetregistration and feeding mechanism in and for combination with a set ofsheets, such as the answer sheets which are the subject of theaforementioned copending U.S. Pat. application by Reckdahl. Each answersheet in the set contains an aperture which is positioned in aprescribed relationship to and closely adjacent a registration edge. Theaperture edge and the registration edge define a holding strip ofvarying width between the aperture and the registration edge, whereinthe narrowest portion of the holding strip defines a separation regionof a predetermined width between the aperture and the registration edge.The narrowest portion of the holding strip defines the separationregion. Portions of the aperture in common with the holding strip andadjacent the registering portions of the aperture edge on opposite sidesof the registering portions from the separation region define twoclearance edges. The two clearance edges converge toward each other in adirection toward the registration edge for enabling the holding strip todeflect to concentrate tension in the separation region when the holdingstrip of a registered sheet is forced against the pin means.

In accordance with the disclosure of the aforementioned copendingReckdahl application, it has been observed that when sheets having theaforesaid limitations are fed from pin means with a predetermined force,reliability of feeding is increased, each fed sheet is consistently andmore cleanly torn in the separation region, and the residue of debris isappreciably reduced. Concentration of tension in the separation regionis increased by providing that the two clearance edges be straightedges.

It is preferred that the registration edge is a straight edge and thatthe aperture is symmetrical about an axis perpendicular to theregistration edge.

The reliability with which the aforesaid sheets may be registered andfed may be further increased by providing certain combinations ofvarious species of answer sheets, pin means and feed means in accordancewith the present invention. Combining the sheets with the sheetregistration and feeding apparatus according to the present inventionimproves reliability in sheet registration and feeding by providingcertain features in the pin means and feed means which are used incombination with a stacked set of sheets such as the set of answersheets described in the aforementioned copending Reckdahl application.Such reliability is also improved by providing certain additionalfeatures in the set of sheets in relation to the particular pin meansand feed means with which the sheets are combined. The sheets mayinclude sheets other than answer sheets.

in accordance with the present invention, the pin means are shaped forregistration with the registering portions of the aperture edge of eachsheet, and the feed means are positioned for engaging the outside sheetof a registered stack of sheets and for feeding the engaged sheet fromthe registered stack with a predetermined force. The feed means includefeed legs which are positioned on each side of the pin means forengaging the outside registered sheet at positions adjacent theregistration edge beyond each side of the aperture; and the feed legsare spaced apart by a predetermined distance for causing deflection ofthe holding strip to concentrate tension in the separation region whenthe holding strip is forced against the pin means by the feed legsfeeding the registered and engaged sheet from the stack. The feed legsare also spaced apart by a predetermined distance for enabling thefeeding of the engaged sheet from the stack; that is, the feed legs mustbe placed close enough together to cause sufficient force to be appliedbetween the holding strip and the pin means to enable the separation ofthe holding strip upon the operation of the feed means. If the feed legsare not placed close enough together to provide this sufficient forcerelationship between the holding strip and the pin means, the feed legsmay ride over or bend the registered sheet rather than feed theregistered sheet from the given position.

The feed means on the feed legs include means for engaging the feed legswith the registration edge of an outside registered sheet for enablingthe feed legs to push against the engaged registration edge to feed theengaged sheet from a registered stack and for applying a force tocompress the stack for aligning the registration edge of the outsideregistered sheet with the feed legs to enable the engagement of the feedlegs with the registration edge. Absent the compression of the stack,the registration edge ofa sheet may be slightly bent so that theregistration edge is not aligned for engagement with both feed legs.

The feed legs are variably disposed to the holding means in response tovariations in the size of a stack; and the feed means include springmeans positioned for providing the force which is applied forcompressing the stack of sheets. These spring means are operativelyresponsive to a variation in the disposition of the feed legs inresponse to a reduction in the size of the stack for decreasing theprovided applied compres sive force as the size of the stack is reduced.

In the embodiment wherein each sheet is of a predetermined thickness,each feed leg includes a step for applying the force for compressing thestack and for engaging the registration edge of the outside registeredsheet. Each step comprises a plate having a surface disposed forpressing against the exposed surface of the outside registered sheetadjacent the registration edge thereof, for applying the compressiveforce, and a riser joined to the pressing surface of the plate, forengaging the registration edge of the outside registered sheet and forpushing against the registration edge to feed the engaged outsideregistered sheet from the stack upon the operation of the feeding means.The thickness of the step provided by the riser is not greater than thethickness of each sheet. The thickness of the step provided by the riseris defined as the distance between the plate and the position where theriser contacts the registration edge of the outside registered sheet.

it is preferred that the riser have a V-shaped edge for pushing againstthe registration edge of the outside registered sheet. The surface ofthe riser which is joined to the pressing surface of the plate isdisposed at an acute angle to the pressing surface and the thickness ofthe step provided by the riser is less than the thickness of each step.However, the thickness of the riser is slightly greater than thethickness of each sheet. The thickness of the riser is defined as thedistance between the ends ofthe arms of the V".

In one preferred embodiment, the registration edge of each sheet issmooth for enabling penetration of the registration edge of the outsideregistered sheet by the V-shaped riser edge and for enabling holding bythe registration edge of the penetrating riser edge. A smooth edge isdefined as the type of edge obtained when cutting paper with a sharpenedguillotine cutter or sharpened slitter cutter in contrast to the type ofedge obtained by cutting paper with a dull slitter cutter or a dullguillotine cutter.

ln a preferred embodiment, wherein each sheet is ofa given width betweenthe aperture and the edge opposite the registration edge, means areprovided for maintaining the fed sheets in the sequence in which theywere originally placed in stacked registration on the pin means. Thesequence maintaining means comprise a stop disposed in relation to thepin means for stopping movement of a fed sheet, wherein the distancebetween the stop and the pin means is less than approximately twice thegiven width, whereby the registration edge ofa fed sheet rests on andoverlapping the opposite edge of an outside registered sheet When thefeed legs including the above-described steps are used in combinationwith the above-described sequence-maintaining means, the force providedby the plate to a sheet during feeding prevents buckling of the sheetnear the registration edge thereof.

Again referring to the set of sheets for each sheet in a set, it ispreferred that the two clearance edges are straight edges; that the pinmeans have a curved holding surface and that the pin means is disposedfor registering the curved holding surface with the two straight edges.It is also preferred that the aperture of each sheet is an isoscelestriangle with the vertex adjacent the separation region and with thebase parallel to the registration edge; that the pin means have asemicircular holding surface and that the pin means is disposed forregistering the flat surface of the pin means with the base of theaperture.

In a preferred embodiment, the dimensions of the registering portions ofthe aperture edge are slightly larger than the corresponding dimensionsof the pin means, thereby preventing a snug registration; and the feedlegs are disposed for dragging across the outside registered sheetduring an interval between the feeding of the fed sheet and theengagement of the next outside registered sheet, which dragging providesa small opening between the pin means and the holding strip of theoutside registered sheet.

A snug registration is undesirable for the following reasons. A snugregistration makes the registering of the sheets on the pin means moredifficult; a snug registration impedes compression of the sheets foraligning the registration edge of the sheets with each step of the feedlegs; and a snug registration increases the likelihood of tearing theedges of the aperture while registering the sheets on the pin means.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 illustrates in perspective asheet registration and feeding apparatus in combination with a set ofsheets.

FIG. 2 illustrates a sheet of a set of answer sheets for use in thecombination illustrated in FIG. 1.

FIG. 3 is another perspective view of the sheet registration and feedingapparatus and sheet set combination illustrated in FIG. 1.

FIG. 4 is a top view of the feed means shown in the sheet registrationand feeding apparatus illustrated in FIGS. 11 and 3.

FIG. 5 is a sectional view taken along and in the direction of line 5-5of FIG. 4, which view illustrates a feed leg with a step attachedthereto for compressing a set of stacked registered answer sheets andfor engaging the outside sheet of the registered stack.

FIG. 6 is a perspective view of an embodiment of feed legs for engagingand feeding the outside sheet of the registered stack, which embodimentis alternative to that shown in FIGS. 1 and 35.

FIGS. 7a7e illustrate various alternative embodiments of theregistration edge, aperture and holding strip of a sheet for use in thecombination of the present invention. Pin means for registration withthe illustrated apertures are shown by dashed line.

DESCRIPTION OF THE PREFERRED EMBODIMENT The combination of a set ofsheets and a sheet registration and feeding apparatus according to thepresent invention is illustrated in FIG. 1. A stacked set of sheets 30is shown in combination with the feed means 32 and the holding means 34.

FIG. 2 illustrates a sheet of a set for use in the combination shown inFIG. 1. Although an answer sheet is illustrated in FIG. 2, the set isnot necessarily a set of answer sheets.

The answer sheet contains an aperture 12 positioned in a prescribedrelationship to and closely adjacent the registration edge 10. The pinmeans 14 are shown by the dashed line in FIG. 2. The aperture edge 13and the registration edge 10 define a holding strip 16 of varying widthbetween the aperture l2 and the registration edge 10. The narrowestportion of the holding strip 16 defines a separation region 18 of apredetermined width between the aperture 12 and the registration edge10. The aperture 12 is symmetrical about a line which is perpendicularto the registration edge 10. The separation region [8 lies along thisline 20.

It is seen that portions of the aperture edge 13 are shaped forregistering the answer sheet with the pin means 14 adjacent theseparation region 18. Two portions of the aperture edge 13 in commonwith the holding strip 16 and adjacent the registering portions 21 onopposite sides of the registering portions 21 from the separation region18 define two clearance edges 22. The two clearance edges 22 convergetoward each other in a direction toward the registration edge 10 andthereby enable the holding strip 16 to deflect to concentrate tension inthe separation region 18 when the holding strip 16 is forced against thepin means 14.

Preferably, the clearance edges 22 are straight edges and the aperture12 is centered along the registration edge 10.

In the preferred embodiment, the set of sheets may be registered with apin means 14, such as a pin having a semicircular cross-sectionaldimension, wherein the diameter is 0.25 inches (approximately 6.4 mm.)and be fed by feed means which feed the answer sheets with apredetermined force which is in the range of 20 to ounces (approximately5.6 to 7.0 ncwtons). In this preferred embodiment, each sheet is a papersheet approximately 4 mils. (approximately 0.1 mm.) thick in which theaperture 12 is an isosceles triangle having a base 0.5 inches(approximately 1.3 cm.) in length parallel to the registration edge 11),and having a separation region 18 of a predetermined width of 22 mils.(approximately 0.56 mm.) between the triangle vertex and theregistration edge 10. The sheet is approximately 1 1 inches(approximately 28 cm.) along the registration edge 10 and has a givenwidth between the aperture 12 and the edge 24 opposite the registrationedge 10 of approximately 4 inches (approximately 10 cm.). The height ofthe triangle is 0.173 inches (approximately 4.4 mm.). DATA" brand OCRBond 200 paper available from the International Paper company New York,N.Y., is preferred, and all sheets in a set preferably have the fiberrunning in the same direction in relation to the registration edge. Thepaper has an average smoothness of 112 Sheffield units.

In one preferred embodiment, answer indication areas are provided oneach surface of the sheet, and apertures 12 and 26 adjacent registrationedges 10 and 24, respectively, are provided, thereby doubling thequestion capacity of each answer sheet.

Answer indications are shown in various answer indication areas of theanswer sheet of FIG. 2.

A stacked set of sheets 30 is shown in combination with the feed means32 and holding means 34 in FIGS. 1 and 35. The holding means 34 comprisepin means 36, a table 38 and guide means such as the bars 40, forreceiving and supporting the set of sheets 30 in stacked registrationwith the pin means 36. The pin means 36 prevent lateral movement of thesheets and the bars 40 in combination with the pin means 36 preventrotational movement. The table 38 is slidably mounted on the frame 41 sothat the pin means 36 can be pulled out from under the feed means 32when a set of sheets is registered on the pin means 36. The feed means32 comprise feed legs 42 and a spring 44 for providing a predeterminedforce to move the feed legs 42 for feeding sheets from the stack 30. Thefeed legs 42 are positioned on each side of the pin means 36 atpositions adjacent the registration edge 10 beyond each side of theaperture 12. The feed legs 42 are attached by supporting members 46, 48and 50 to a baseplate (not shown) as described in the aforementionedU.S. Pat. application by Roche. This baseplate is slidably mounted in aholder (not shown) which is positioned in a stationary relationship tothe frame 41 supporting the holding means 34. The apertures 52 in thesupporting members 50 are for coupling the feed means 32 to thebaseplate. The baseplate and the feed means 32 may be slidablypositioned in either a cocked or a forward position. The feed means 32are shown in the cocked position in FIGS. 1 and 3-5. The feed legs 42when operated move from this cocked position to a forward position forremoving a sheet such as fed sheet 54 from the registered stack 30 to astopped position, such as that in which the fed sheet 54 is shown.

The feed means 32 include means, such as the steps 56 for engaging thefeed legs 42 with the registration edge 10 of an outside registeredsheet 58 of the stack 30 for enabling the feed legs 42 to push againstthe engaged outside registered sheet 58 to feed the engaged sheet 58from the stack 30. The steps 56 also are means by which the feed means32 apply a force to compress the stack 30 for aligning the registrationedge 10 of the outside sheet 58 with the feed legs 42 to enable the feedlegs 42 to engage the registration edge 10.

The table 38 includes a bench 59 positioned beneath the cocked positionof the feed legs 42. The steps 56 rest on the bench 59 when no sheetsare registered on the pin means 36.

Each step 56 comprises a plate 60 and a riser 62. The plate 60 isdisposed for pressing against the exposed surface 64 of the outsideregistered sheet 58. The plate 60 is also disposed adjacent theregistration edge 10 of the outside registered sheet 58 to apply theforce for compressing the stack 30. This applied force is provided byspring means such as the spring 66. The riser 62 is joined to thepressing surface 68 of the plate 60 for engaging the registration edge10 of the outside registered sheet 58 and for pushing against theregistration edge 10 to feed an engaged outside registered sheet 58 fromthe stack 30 upon the operation of the feeding means 32 Each sheet inthe stack 30 is of a predetermined thickness and the thickness of thestep provided by the riser 62 is not greater than the thickness of eachsheet of stack 30. The riser 62 has a V-shaped edge for pushing againstthe registration edge 10 of the outside registered sheet 58. It is seenin FIG. that the surface 70 of the riser 62 which is joined to thepressing surface 68 of the plate 60 is disposed at an acute angle to thepressing surface 68. The thickness of the step provided by the riser 62is the distance between the point of the V" where the riser engages theregistration edge and the pressing surface 68 of the plate 60, thethickness of the riser 62, however, being the distance between the endsof the arms of the V. The thickness of the riser 62 is slightly greaterthan the thickness of each sheet of the stack 30, thereby alleviatingthe frictional drag between the outside sheet 58 and the second sheet 78when the outside sheet 58 is fed and the riser 62 rides on the secondsheet 78. The registration edge 10 of each sheet is preferably smoothfor enabling the V-shaped edge of the riser 62 to penetrate theregistration edge 10 for enabling the registration edge 10 to hold thepenetrating edge of the riser 62.

An alternative embodiment of the steps 56 is shown in FIG. 6. In thisalternative embodiment, the steps 72 are also attached to the feed legs42. However, in this embodiment the riser edge is a vertical surfaceprovided by member 74 and the plate 76 is disposed at a slight angle tothe horizontal surface of the outside registered sheet 58 of the stack30.

The force provided by the spring means 66 is transmitted to the feedlegs 42 by the supporting member 48. Referring to FIG. I. it is seenthat the spring 66 is fastened to the supporting member 50 by fasteningmember 80. The other end of the spring 66 is fastened to an extension 82of the supporting member 48 which passes through an aperture 84 in thesupporting member 50. Extension 82 is loosely pivotally connected tosupporting member 50 by means of pin 85. The feed legs 42 are therebyself-leveling so that each feed leg 42 can engage the registration edge10 of the outside registered sheet 58. It is seen by this combination ofspring means 66, supporting member 48 and feed legs 42 that the feedlegs 42 are variably disposed to the holding means 34 in response tovariations in the size of the registered stack 30 and that the springmeans 66 are operatively responsive to a variation in the disposition ofthe feed legs 42 in response to a reduction in size of the registeredstack 30 for decreasing the provided applied force as the size of thestack 30 is reduced.

The feed legs 42 are centered about the pin means 36 by supportingmember 46 and the rails 86.

Means are also provided for maintained fed sheets such as sheet 54 inthe sequence in which stacked in the registered stack 30. Thesequence-maintaining means comprise a stop 88 which is disposed on theholding means 34 for stopping movement of each fed sheet 54. Each sheetof the stack 30 is of a given width between the aperture 12 and the edge24 opposite the registration edge 10. The distance between the stop 88and the pin means 36 is less than approximately twice the given widthbetween the aperture 12 and the opposite edge 24. By so placing the stop88 at this predetermined distance from the pin means 36, theregistration edge 10 of a fed sheet rests on and overlapping theopposite edge 24 ofthe outside registered sheet 58 of the stack 30.Therefore, as each sheet 54 is fed from the stack 30, it is positionedbeneath the previously fed sheets 54 and the fed sheets are maintainedin the same sequence as in which they were originally stacked.

The feed force of the feed means 32 is greater than the force requiredto separate the sheet at the separation region 18 plus the frictionalforce provided upon operation of the feed means 32 between the outsideregistered sheet 58 and the second registered sheet 78 due to thepressure provided by the plates 60.

When the sequence-maintaining means 88 is included the feed force of thefeed means 32 is greater than the force required to separate the sheetsat the separation region 18 plus the frictional force provided uponoperation of the feed means 32 between the outside registered sheet 58and the second registered sheet 78 due to the pressure provided by theplates 60 plus the frictional resistance force due to the weight of thestack of the removed sheets 54 inresting upon the sheets remaining inthe stack 30.

Also, the coefficient of friction of the table 38 is preferably as largeas the coefficient of friction of each sheet in the stack 30.

The stiffness of each sheet is sufficient to prevent buckling of thebottom sheet of the stack 30 ofa predetermined quantity of sheets whenfed from the pin means 36 beneath the stack of fed sheets 54.

For seriatim feeding of sheets having the dimensions set forth for a setof answer sheets such as is illustrated in FIG. 2, the centers of thefeed legs 42 are spaced apart by from 0.69 to 0.81 inches (approximately1.8 to 2.1 cm.). The plates are each 0.38 inches (approximately 9.7 mm.)(parallel to the registration edge 10) by 0.5 inches (approximately 1.3cm.) and 0.06 inches (approximately 1.5 mm.) thick. The spring 44, whenin a cocked position, provides a force in the range of from 25 to 30ounces (7.0 to 8.3 newtons). When the feed means are operated, thepredetermined feeding force provided at the feed legs 42 from the spring44 is in the range of from 20 to 25 ounces (5.6 to 7.0 newtons). Thecompressive force applied at the plates 60, which force is provided bythe spring 66, is in the range of from 5 to 9 ounces 1.4 to 2.5 newtons). The stiffness of the paper sheets is approximately 2.05 Taberstiffness units. The foregoing dimensions are for the embodimentincluding the sequence-maintaining means.

It has been found that various combinations of registration edge 10configurations, aperture 12 configurations and pin means 14configurations according to the present invention provide reliable sheetfeeding. These various combinations are illustrated in FIG. 7. In allfive configurations shown, as well as in the configurations shown inFIG. 2, the width of the separation region 18 between the aperture 12and the registration edge 10 is a predetermined width. The registrationedge may include a rectangular notch as shown in FIG. 7a a curved groove92 as shown in FIGS. 7b and 7d, or a slit 94 as shown in FIG. 7c. In thecombination shown in FIG. 70, the predetermined width of the separationregion 18 is the distance between the aperture 12 and the end of theslit 94 nearest the the aperture 12.

The pin means 14 may be semicircular as illustrated in FIGS. 2, 7a, 7bor 7d, or round, as illustrated in FIGS. 70 and 7e. Other pin shapes mayalso be used, however, the illustrated shapes are preferred.

The combination of a pin having a curved surface with an aperture havingstraight edges such as illustrated in FIGS. 2, 7a, 7b and 7c was foundto provide the best combination of reliable feeding and consistent cleanseparation in the separation region. Providing curved aperture edgesadjacent the holding strip 16 in combination with the pin having acurved surface such as is illustrated in FIGS. 7d and 7e also producedreliable feeding, however, the tears for the configuration illustratedin FIG. 7d, while consistently in the separation region, were sometimesragged. The registration provided by the combination of FIG. 7d is lessprecise than provided by the other combinations shown, but is acceptablewhen synchronization tolerances permit less precise registration.

The significant feature for all combinations of aperture 12 and pinmeans 14 is that portions of the edge of the aperture 12 be shaped forregistering with the pin means 14 to prevent lateral movement of thesheet and that clearance edges 22 be provided to enable the holdingstrip 16 to deflect to concentrate tension in the separation region whenthe pin means 14 is forced against the holding strip 16 upon theoperation of the feed means 32. Reliable feeding and clean, consistentseparation in the separation region is also improved by providing thatthe aperture 12 be symmetrical about an axis 20 which is perpendicularto the registration edge 10.

We claim:

I. In combination:

a set of sheets adapted for stacked registration with a pin apply a saidforce; and a riser joined to the pressing surmeans and for seriatimfeeding from a said stack, each sheet including a registration edge andcontaining an aperture which is positioned in a prescribed relationshipface of the plate for engaging the registration edge of a said outsideregistered sheet and for pushing against the registration edge to feed asaid engaged outside registered to and closely adjacent the registrationedge, the aperture sheet from a said stack upon said feeding by the feededge and the registration edge defining a holding strip of means,wherein the thickness of the step provided by the varying width betweenthe ap rtur nd th r i ati riser is not greater than the thickness ofeachsheet.

edge; the narrowest portion ofthe holding strip defining a 5. A sheetregistration and feeding combination according separation region of apredetermined width between the to Claim 4, further Characterized y thefeature that aperture and the registration edge; portions of the apertheriser has p edge for Pushing against the regisw d b i h d f registeringh sheet with a tration edge of a said outside registered sheet, whereinid i means dj h Separation i two the surface of the riser which isjoined to the pressing surtions of the aperture edge in common with theholding face the Plate is dispose? at an acute angle to the strip andadjacent the registering portions of the aperture Pressmg Surface, andwherem the thlckhess of the step provided by the riser is less than thethickness of each sheet.

6. A sheet registration and feeding combination according to claim 5,further characterized by the feature that the registration edge of eachsheet is smooth for enabling penetration of the registration edge of asaid outside rcgistered sheet by the riser edge and for enabling holdingby the registration edge of a said penetrating riser edge.

7. A sheet registration and feeding combination according to claim 5,further characterized by the feature that the thickness of the riser isslightly greater than the thickness of each sheet.

8. A sheet registration and feeding combination according to claim 1,wherein each sheet is of a given width between the aperture and the edgeopposite the registration edge, further characterized by means formaintaining said fed sheet in the sequence in which stacked, comprisinga stop disposed on the holding means for stopping move- 35 ment of asaid fed sheet, wherein the distance between the stop and the pin meansis less than approximately twice the given width, whereby theregistration edge of a said fed sheet rests on the opposite edge of asaid outside registered sheet. I

9. A sheet registration and feeding combination according to claim 8,further characterized by the feature that the feed means include meansfor engaging the feed legs with the registration edge of a said outsideregistered sheet for enabling the feed legs to push against a saidengaged registration edge to feed a said engaged sheet from a saidstack; and the feed means include means for applying a force to compressa said stack for aligning the registration edge of a said outsideregistered sheet with the feed legs to enable said engagement with asaid registra- 50 tion edge;

each sheet is ofa predetermined thickness; and each feed leg includes astep for applying a said force to compress a said stack and for engagingthe registration edge of a said outside registered sheet, wherein eachstep 55 comprises a plate having a surface disposed for pressing againstthe exposed surface of a said outside registered sheet adjacent theregistration edge of a said outside registered sheet to apply a saidforce; and a riser joined to the pressing surface of the plate forengaging the registration edge of a said outside registered sheet andfor pushing against the edge on opposite sides of the registeringportions from the separation region defining two clearance edges, whichtwo clearance edges converge toward each other in a direction toward theregistration edge for enabling the holding strip to deflect toconcentrate tension in the separation region when the holding strip of asaid registered sheet is forced against a said pin means; and

a sheet registration and feeding apparatus comprising holding means forreceiving and supporting the set of sheets in said stacked registrationincluding pin means shaped for registration with the registeringportions of the aperture edge of each sheet of the set, and guide meansdisposed relative to the pin means for registration with theregistration edge of each said stacked sheet; and

feed means positioned for engaging the outside sheet of a saidregistered stack, and for feeding a said engaged sheet from a saidregistered stack with a predetermined force, which feed means includefeed legs positioned on each side of the pin means for engaging a saidoutside registered sheet at positions adjacent the registration edgebeyond each side of the aperture, wherein the feed legs are spaced apartby a predetermined distance for causing deflection of the holding stripfor concentrating tension in the separation region when the holdingstrip of a said registered and engaged sheet is forced against the pinmeans by the feed means feeding a said registered and engaged sheet froma said stack. and for enabling the feeding ofa said engaged sheet from asaid stack.

2. A sheet registration and feeding combination according to claim I,further characterized by the feature that the feed means include meansfor engaging the feed legs with the registration edge of a said outsideregistered sheet for enabling the feed legs to push against a saidengaged registration edge to feed a said engaged sheet from a saidstack; and the feed means include means for applying a force to compressa said stack for aligning the registration edge of a said outsideregistered sheet with the feed legs to enable said engagement with asaid registration edge.

3. A sheet registration and feeding combination according to claim 2,further characterized by the feature that the feed legs are variablydisposed to the holding means in response to variations in the size of asaid stack; and the feed means include spring means for providing a saidapplied force, which spring means are operatively responsive to avariation in the disposition of the feed legs in response to a reductionin the size of a said stack, for decreasing said provided applied forceas the size of a said registration edge to feed a said engaged outsideregistered sheet from a said stack upon said feeding by the feed means,wherein the thickness of the step provided by the stack is reduced.

4. A sheet registration and feeding combination according to claim 2,further characterized by the feature that each sheet is ofapredetermined thickness;

each feed leg includes a step for applying a said force to compress asaid stack and for engaging the registration edge of a said outsideregistered sheet, wherein each step comprises a plate having a surfacedisposed for pressing against the exposed surface of a said outsideregistered sheet adjacent the registration edge of a said outsideregistered sheet to riser is not greater than the thickness of eachsheet; whereby a said provided force is applied by the plate to a saidfed sheet during said feeding for preventing buckling near theregistration edge of a said fed sheet. 10. A sheet registration andfeeding combination according to claim 1, further characterized by thefeature that in each sheet the two clearance edges are straight edges;

and the pin means has a curved holding surface and is disposed forregistration of the curved surface with said two straight edges of asaid sheet.

1]. A sheet registration and feeding combination according to claim I,further characterized by the feature that in each sheet the aperture isan isosceles triangle with the vertex adjacent the separation region andthe base parallel to the registration edge; and

the pin means has a semicircular holding surface for registration with asaid sheet, wherein the pin means is disposed for registration of theflat surface of the pin means with the base ofthe aperture of a saidsheet.

12. A sheet registration and feeding combination according to claim 1,further characterized by the feature that the dimensions defined by theregistering portions of the aperture edge are slightly larger than thecorresponding dimensions of the pin means for preventing a snugregistration.

13. A sheet registration and feeding combination according to claim 12,further characterized by the feature that the feed legs are disposed fordragging across a said outside registered sheet during an intervalbetween the feeding of a fed sheet and the engagement of a said outsideregistered sheet, which dragging provides a small opening between thepin means and the holding strip of a said outside registered sheet.

14. A sheet registration and feeding apparatus for registering andfeeding a set of sheets which is adapted for stacked registration with apin means and for seriatim feeding from a said stack, each said sheetincluding a registration edge and containing an aperture which ispositioned in a prescribed relationship to the answer indication areas,and is positioned in a prescribed relationship to and closely adjacent asaid registration edge, a said aperture edge and a said registrationedge defining a holding strip of varying width between a said apertureand a said registration edge; the narrowest portion of a said holdingstrip defining a separation region of a predetermined width between asaid aperture and a said registration edge; portions of a said apertureedge being shaped for registering each sheet with a said pin meansadjacent a said separation region; two portions ofa said aperture edgein common with a said holding strip and adjacent said registeringportions of a said aperture edge on opposite sides of said registeringportions from a said separation region defining two clearance edges,which two clearance edges converge toward each other in a directiontoward a said registration edge for enabling a said holding strip todeflect to concentrate tension in a said separation region when a saidholding strip of a said registered sheet is forced against a said pinmeans, comprising holding means for receiving and supporting a said setof sheets in said stacked registration including pin means shaped forregistration with said registering portions of a said aperture edge ofeach sheet of a said set, and guide means disposed relative to the pinmeans for registration with a said registration edge of each saidstacked sheet; and

feed means positioned for engaging the outside sheet of a saidregistered stack, and for feeding a said engaged sheet form a saidregistered stack with a predetermined force, which feed means includefeed legs positioned on each side of the pin means for engaging a saidoutside registered sheet at positions adjacent a said registration edgebeyond each side of a said aperture, wherein the feed legs are spacedapart by a predetermined distance for causing deflection of a saidholding strip for concentrating tension in a said separation region whena said holding strip of a said registered and engaged sheet is forcedagainst the pin means by the feed means feeding a said registered andengaged sheet from a said stack, and for enabling the feeding of a saidengaged sheet from a said stack.

15. A sheet registration and feeding combination according to claim 14,further characterized by the feature that the feed means include meansfor engaging the feed legs with a said registration edge of a saidoutside registered sheet for enabling the feed legs to push against asaid engaged registration edge to feed a said engaged sheet from a saidstack; and the feed means include means for applying a force to compressa said stack for aligning a said registration edge of a said outsideregistered sheet with the feed legs to enable said engagement with asaid registration edge. I

16. A sheet registration and feeding combination according to claim 15,further characterized by the feature that the feed legs are variablydisposed to the holding means in response to variations in the size of asaid stack; and the feed means include spring means for providing a saidapplied force, which spring means are operatively responsive to avariation in the disposition of the feed legs in response to a reductionin the size of a said stack, for decreasing said provided applied forceas the size ofa said stack is reduced.

17. A sheet registration and feeding combination according to claim 15,wherein each said sheet is of a predetermined thickness; furthercharacterized by the feature that each feed leg includes a step forapplying a said force to compress a said stack and for engaging a saidregistration edge ofa said outside registered sheet, wherein each stepcomprises a plate having a surface disposed for pressing against thesurface of a said outside registered sheet adjacent a said registrationedge of a said outside registered sheet to apply a said force; and ariser joined to the pressing surface of the plate for engaging a saidregistration edge of a said outside registered sheet and for pushingagainst a said registration edge to feed a said engaged outsideregistered sheet from a said stack upon said feeding by the feed means,wherein the thickness of the step provided by the riser is not greaterthan a said thickness of each said sheet.

18. A sheet registration and feeding combination according to claim 17,further characterized by the feature that the riser has a V-shaped edgefor pushing against a said registration edge of a said outsideregistered sheet, wherein the surface of the riser which is joined tothe pressing surface of the plate is disposed at an acute angle to thepressing surface, and wherein the thickness of the step provided by theriser is less than the thickness of each said sheet.

19. A sheet registration and feeding combination according toclaim 18,further characterized by the feature that the thickness of the riser isslightly greater than the thickness of each said sheet.

20. A sheet registration and feeding combination according to claim 14,wherein each said sheet is of a given width between a said aperture andthe edge opposite a said registration edge, further characterized bymeans for maintaining said fed sheets in the sequence in which stacked,comprising a stop disposed on the holding means for stopping movement ofa said fed sheet, wherein the distance between the stop and the pinmeans is less than approximately twice a said given width, whereby asaid registration edge of a said fed sheet rests on a said opposite edgeof a said outside registered sheet.

21. A sheet registration and feeding combination according to claim 20,wherein each said sheet is of a predetermined thickness, furthercharacterized by the feature that the feed means include means forengaging the feed legs with a said registration edge of a said outsideregistered sheet for enabling the feed legs to push against a saidengaged registration edge to feed a said engaged sheet from a saidstack; and the feed means include means for applying a force to compressa said stack for aligning a said registration edge ofa said outsideregistered sheet with the feed legs to enable said engagement with asaid registration edge; and

each feed leg includes a step for applying a said force to compress asaid stack and for engaging a said registration edge of a said outsideregistered sheet, wherein each step comprises a plate having a surfacedisposed for pressing against the exposed surface of a said outsideregistered sheet adjacent a said registration edge of a said outsideregistered sheet to apply a said force; and a riser joined to thepressing surface of the plate for engaging a said registration edge of asaid outside registered sheet and for pushing against a saidregistration edge to feed a said engaged outside registered sheet from asaid stack upon said feeding by the feed means, wherein the thickness ofthe step provided by the riser is not greater than a said thickness ofeach sheet;

whereby a said provided force is applied by the plate to a said fedsheet during said feeding for preventing buckling near a saidregistration edge of a said fed sheet.

22. A sheet registration and feeding combination according to claim 14,wherein in each said sheet said two clearance edges are straight edges,further characterized by the feature that the pin means has a curvedholding surface and is disposed for registration of the curved surfacewith said two straight edges of a said sheet.

23. A sheet registration and feeding combination according to claim 13,wherein in each said sheet a said aperture is an isosceles triangle withthe vertex adjacent a said separation region and the base parallel to asaid registration edge, further characterized by the feature that thepin means has a semicircular holding surface for registration with asaid sheet, wherein the pin means is disposed for registration of theflat surface of the pin means with a said base ofa said aperture ofasaid sheet. 24. A sheet registration and feeding combination accordingto claim 14, wherein the dimensions defined by said registering portionsof a said aperture edge is slightly larger than the correspondingdimensions of the pin means for preventing a snug registration, furthercharacterized by the feature that the feed legs are disposed fordragging across a said outside registered sheet during an intervalbetween the feeding of a fed sheet and the engagement of said outsideregistered sheet, which dragging provides a small opening between thepin means and a said holding strip ofa said outside registered sheet.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,586318 Dated June 22 1971 Inventor(s) Segwald J. Reckdahl 8: Donald W.Folske It is certified that error appears in the above-identified patentand that said Letters Patent are hereby corrected as shown below:

In the Specification:

Column 6, line 9, change "200" to 20# Column 7, line 8, change"maintained" to maintaining Signed and sealed this 2nd day of November 1971 (SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer ActingCommissioner of Patents FORM po-aoso (Io-s9] USCQMWDC 60375.?

R U 5 GOVERNMENT PRINTING OFFICE 1 1909 O-L=5G-3 l

1. In combination: a set of sheets adapted for stacked registration witha pin means and for seriatim feeding from a said stack, each sheetincluding a registration edge and containing an aperture which ispositioned in a prescribed relationship to and closely adjacent theregistration edge, the aperture edge and the registration edge defininga holding strip of varying width between the aperture and theregistration edge; the narrowest portion of the holding strip defining aseparation region of a predetermined width between the aperture and theregistration edge; portions of the aperture edge being shaped forregistering each sheet with a said pin means adjacent the separationregion; two portions of the aperture edge in common with the holdingstrip and adjacent the registering portions of the aperture edge onopposite sides of the registering portions from the separation regiondefining two clearance edges, which two clearance edges converge towardeach other in a direction toward the registration edge for enabling theholding strip to deflect to concentrate tension in the separation regionwhen the holding strip of a said registered sheet is forced against asaid pin means; and a sheet registration and feeding apparatuscomprising holding means for receiving and supporting the set of sheetsin said stacked registration including pin means shaped for registrationwith the registering portions of the aperture edge of each sheet of theset, and guide means disposed relative to the pin means for registrationwith the registration edge of each said stacked sheet; and feed meanspositioned for engaging the outside sheet of a said registered stack,and for feeding a said engaged sheet from a said registered stack with apredetermined force, which feed means include feed legs positioned oneach side of the pin means for engaging a said outside registered sheetat positions adjacent the registration edge beyond each side of theaperture, wherein the feed legs are spaced apart by a predetermineddistance for causing deflection of the holding strip for concentratingtension in the separation region when the holding strip of a saidregistered and engaged sheet is forced against the pin means by the feedmeans feeding a said registered and engaged sheet from a said stack, andfor enabling the feeding of a said engaged sheet from a said stack.
 2. Asheet registration and feeding combination according to claim 1, furthercharacterized by the feature that the feed means include means forengaging the feed legs with the registration edge of a said outsideregistered sheet for enabling the feed legs to push against a saidengaged registration edge to feed a said engaged sheet from a saidstack; and the feed means include means for applying a force to compressa said stack for aligning the registration edge of a said outsideregistered sheet with the feed legs to enable said engagement with asaid registration edge.
 3. A sheet registration and feeding combinationaccording to claim 2, further characterized by the feature that the feedlegs are variably disposed to the holding means in response tovariations in the size of a said stack; and the feed means includespring means for providing a said applied force, which spring means areoperatively responsive to a variation in the disposition of the feedlegs in response to a reduction in the size of a said stack, fordecreasing said provided applied force as the size of a said stack isreduced.
 4. A sheet registration and feeding combination according toclaim 2, further characterized by the feature that each sheet is of apredetermined thickness; each feed leg includes a step for applying asaid force to compress a said stack and for engaging the registrationedge of a said outside registered sheet, wherein each step comprises aplate having a surface disposed for pressing against the exposed surfaceof a said outside registered sheet adjacent the registration edge of asaid outside registered sheet to apply a said force; and a riser joinedto the pressing surface of the plate for engaging the registration edgeof a said outside registered sheet and for pushing against theregistration edge to feed a said engaged outside registered sheet from asaid stack upon said feeding by the feed means, wherein the thickness ofthe step provided by the riser is not greater than the thickness of eachsheet.
 5. A sheet registration and feeding combination according toclaim 4, further characterized by the feature that the riser has aV-shaped edge for pushing against the registration edge of a saidoutside registered sheet, wherein the surface of the riser which isjoined to the pressing surface of the plate is disposed at an acuteangle to the pressing surface, and wherein the thickness of the stepprovided by the riser is less than the thickness of each sheet.
 6. Asheet registration and feeding combination according to claim 5, furthercharacterized by the feature that the registration edge of each sheet issmooth for enabling penetration of the registration edge of a saidoutside registered sheet by the riser edge and for enabling holding bythe registration edge of a said penetrating riser edge.
 7. A sheetregistration and feeding combination according to claim 5, furthercharacterized by the feature that the thickness of the riser is slightlygreater than the thickness of each sheet.
 8. A sheet registration andfeeding combination according to claim 1, wherein each sheet is of agiven width between the aperture and the edge opposite the registrationedge, further characterized by means for maintaining said fed sheet inthe sequence in which stacked, comprising a stop disposed on the holdingmeans for stopping movement of a said fed sheet, wherein the distancebetween the stop and the pin means is less than approximately twice thegiven width, whereby the registration edge of a said fed sheet rests onthe opposite edge of a said outside registered sheet.
 9. A sheetregistration and feeding combination according to claim 8, furthercharacterized by the feature that the feed means include means forengaging the feed legs with the registration edge of a said outsideregistered sheet for enabling the feed legs to push against a saidengaged registration edge to feed a said engaged sheet from a saidstack; and the feed means include means for applying a force to compressa said stack for aligning the registration edge of a said outsideregistered sheet with the feed legs to enable said engagement with asaid registration edge; each sheet is of a predeterMined thickness; andeach feed leg includes a step for applying a said force to compress asaid stack and for engaging the registration edge of a said outsideregistered sheet, wherein each step comprises a plate having a surfacedisposed for pressing against the exposed surface of a said outsideregistered sheet adjacent the registration edge of a said outsideregistered sheet to apply a said force; and a riser joined to thepressing surface of the plate for engaging the registration edge of asaid outside registered sheet and for pushing against the registrationedge to feed a said engaged outside registered sheet from a said stackupon said feeding by the feed means, wherein the thickness of the stepprovided by the riser is not greater than the thickness of each sheet;whereby a said provided force is applied by the plate to a said fedsheet during said feeding for preventing buckling near the registrationedge of a said fed sheet.
 10. A sheet registration and feedingcombination according to claim 1, further characterized by the featurethat in each sheet the two clearance edges are straight edges; and thepin means has a curved holding surface and is disposed for registrationof the curved surface with said two straight edges of a said sheet. 11.A sheet registration and feeding combination according to claim 1,further characterized by the feature that in each sheet the aperture isan isosceles triangle with the vertex adjacent the separation region andthe base parallel to the registration edge; and the pin means has asemicircular holding surface for registration with a said sheet, whereinthe pin means is disposed for registration of the flat surface of thepin means with the base of the aperture of a said sheet.
 12. A sheetregistration and feeding combination according to claim 1, furthercharacterized by the feature that the dimensions defined by theregistering portions of the aperture edge are slightly larger than thecorresponding dimensions of the pin means for preventing a snugregistration.
 13. A sheet registration and feeding combination accordingto claim 12, further characterized by the feature that the feed legs aredisposed for dragging across a said outside registered sheet during aninterval between the feeding of a fed sheet and the engagement of a saidoutside registered sheet, which dragging provides a small openingbetween the pin means and the holding strip of a said outside registeredsheet.
 14. A sheet registration and feeding apparatus for registeringand feeding a set of sheets which is adapted for stacked registrationwith a pin means and for seriatim feeding from a said stack, each saidsheet including a registration edge and containing an aperture which ispositioned in a prescribed relationship to the answer indication areas,and is positioned in a prescribed relationship to and closely adjacent asaid registration edge, a said aperture edge and a said registrationedge defining a holding strip of varying width between a said apertureand a said registration edge; the narrowest portion of a said holdingstrip defining a separation region of a predetermined width between asaid aperture and a said registration edge; portions of a said apertureedge being shaped for registering each sheet with a said pin meansadjacent a said separation region; two portions of a said aperture edgein common with a said holding strip and adjacent said registeringportions of a said aperture edge on opposite sides of said registeringportions from a said separation region defining two clearance edges,which two clearance edges converge toward each other in a directiontoward a said registration edge for enabling a said holding strip todeflect to concentrate tension in a said separation region when a saidholding strip of a said registered sheet is forced against a said pinmeans, comprising holding means for receiving and supporting a said setof sheets in said stacked registration including pin meaNs shaped forregistration with said registering portions of a said aperture edge ofeach sheet of a said set, and guide means disposed relative to the pinmeans for registration with a said registration edge of each saidstacked sheet; and feed means positioned for engaging the outside sheetof a said registered stack, and for feeding a said engaged sheet form asaid registered stack with a predetermined force, which feed meansinclude feed legs positioned on each side of the pin means for engaginga said outside registered sheet at positions adjacent a saidregistration edge beyond each side of a said aperture, wherein the feedlegs are spaced apart by a predetermined distance for causing deflectionof a said holding strip for concentrating tension in a said separationregion when a said holding strip of a said registered and engaged sheetis forced against the pin means by the feed means feeding a saidregistered and engaged sheet from a said stack, and for enabling thefeeding of a said engaged sheet from a said stack.
 15. A sheetregistration and feeding combination according to claim 14, furthercharacterized by the feature that the feed means include means forengaging the feed legs with a said registration edge of a said outsideregistered sheet for enabling the feed legs to push against a saidengaged registration edge to feed a said engaged sheet from a saidstack; and the feed means include means for applying a force to compressa said stack for aligning a said registration edge of a said outsideregistered sheet with the feed legs to enable said engagement with asaid registration edge.
 16. A sheet registration and feeding combinationaccording to claim 15, further characterized by the feature that thefeed legs are variably disposed to the holding means in response tovariations in the size of a said stack; and the feed means includespring means for providing a said applied force, which spring means areoperatively responsive to a variation in the disposition of the feedlegs in response to a reduction in the size of a said stack, fordecreasing said provided applied force as the size of a said stack isreduced.
 17. A sheet registration and feeding combination according toclaim 15, wherein each said sheet is of a predetermined thickness;further characterized by the feature that each feed leg includes a stepfor applying a said force to compress a said stack and for engaging asaid registration edge of a said outside registered sheet, wherein eachstep comprises a plate having a surface disposed for pressing againstthe surface of a said outside registered sheet adjacent a saidregistration edge of a said outside registered sheet to apply a saidforce; and a riser joined to the pressing surface of the plate forengaging a said registration edge of a said outside registered sheet andfor pushing against a said registration edge to feed a said engagedoutside registered sheet from a said stack upon said feeding by the feedmeans, wherein the thickness of the step provided by the riser is notgreater than a said thickness of each said sheet.
 18. A sheetregistration and feeding combination according to claim 17, furthercharacterized by the feature that the riser has a V-shaped edge forpushing against a said registration edge of a said outside registeredsheet, wherein the surface of the riser which is joined to the pressingsurface of the plate is disposed at an acute angle to the pressingsurface, and wherein the thickness of the step provided by the riser isless than the thickness of each said sheet.
 19. A sheet registration andfeeding combination according to claim 18, further characterized by thefeature that the thickness of the riser is slightly greater than thethickness of each said sheet.
 20. A sheet registration and feedingcombination according to claim 14, wherein each said sheet is of a givenwidth between a said aperture and the edge opposite a said registrationedge, further characteRized by means for maintaining said fed sheets inthe sequence in which stacked, comprising a stop disposed on the holdingmeans for stopping movement of a said fed sheet, wherein the distancebetween the stop and the pin means is less than approximately twice asaid given width, whereby a said registration edge of a said fed sheetrests on a said opposite edge of a said outside registered sheet.
 21. Asheet registration and feeding combination according to claim 20,wherein each said sheet is of a predetermined thickness, furthercharacterized by the feature that the feed means include means forengaging the feed legs with a said registration edge of a said outsideregistered sheet for enabling the feed legs to push against a saidengaged registration edge to feed a said engaged sheet from a saidstack; and the feed means include means for applying a force to compressa said stack for aligning a said registration edge of a said outsideregistered sheet with the feed legs to enable said engagement with asaid registration edge; and each feed leg includes a step for applying asaid force to compress a said stack and for engaging a said registrationedge of a said outside registered sheet, wherein each step comprises aplate having a surface disposed for pressing against the exposed surfaceof a said outside registered sheet adjacent a said registration edge ofa said outside registered sheet to apply a said force; and a riserjoined to the pressing surface of the plate for engaging a saidregistration edge of a said outside registered sheet and for pushingagainst a said registration edge to feed a said engaged outsideregistered sheet from a said stack upon said feeding by the feed means,wherein the thickness of the step provided by the riser is not greaterthan a said thickness of each sheet; whereby a said provided force isapplied by the plate to a said fed sheet during said feeding forpreventing buckling near a said registration edge of a said fed sheet.22. A sheet registration and feeding combination according to claim 14,wherein in each said sheet said two clearance edges are straight edges,further characterized by the feature that the pin means has a curvedholding surface and is disposed for registration of the curved surfacewith said two straight edges of a said sheet.
 23. A sheet registrationand feeding combination according to claim 13, wherein in each saidsheet a said aperture is an isosceles triangle with the vertex adjacenta said separation region and the base parallel to a said registrationedge, further characterized by the feature that the pin means has asemicircular holding surface for registration with a said sheet, whereinthe pin means is disposed for registration of the flat surface of thepin means with a said base of a said aperture of a said sheet.
 24. Asheet registration and feeding combination according to claim 14,wherein the dimensions defined by said registering portions of a saidaperture edge is slightly larger than the corresponding dimensions ofthe pin means for preventing a snug registration, further characterizedby the feature that the feed legs are disposed for dragging across asaid outside registered sheet during an interval between the feeding ofa fed sheet and the engagement of said outside registered sheet, whichdragging provides a small opening between the pin means and a saidholding strip of a said outside registered sheet.